posted by Stacy on .
Determine the number of bromide ions in solution when 4.23 g of magnesium bromide and 1.21 g of potassium bromide are dissolved in 120mL of water.
Please explain not sure how to even start this problem, thanks!
Convert 4.23 g MgBr2 to moles and multiply that by 2 to obtain moles Br^- from MgBr2. moles = grams/molar mass.
Convert 1.21 g KBr the same way. Add the moles Br^- together to obtain total moles, then remember that 1 mole of Br^- ions will contain 6.022E23 ions.
4.23g MgBr2 Moles= grams/molar mass
4.23/184.113 = 0.023 moles
1.21g KBr Moles= grams/molar mass
1.21/119.002 = 0.033
and than what? I add those two #'s together? 0.033 + 0.023 = 0.033
and I don't know what you mean by 1 mole of Br- ions will contain 6.022e23 ions where did you get that info?